During install I'm sure it did....as will any other program. If it won't simply run without administrator access, or worse yet, writes to the registry as a matter of normal operation then I'd chunk it.
Not my choice. But I did win in another way over the constant messing with the registry -- I made her a VM to play the games on, so when things get mucked up I simply delete the virtual hard drive and copy the original one over again.
But a simpler way to explain this is in automatic updates. You have to be admin in Windows for them to work. In Mac, you're just told to type in the admin password so the updates can install. It's simply a great thing about UNIX that you almost never need to run in root (=Windows Administrator). I know Microsoft tried to fix this in Vista, but somewhere along the way it went horribly wrong.